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path: root/fs/xfs/libxfs/xfs_defer.c
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2018-07-26xfs: make deferred processing safe for embedded dfopsBrian Foster
xfs_defer_finish() has a couple quirks that are not safe with respect to the upcoming internal dfops functionality. First, xfs_defer_finish() attaches the passed in dfops structure to ->t_dfops and caches and restores the original value. Second, it continues to use the initial dfops reference before and after the transaction roll. These behaviors assume that dop is an independent memory allocation from the transaction itself, which may not always be true once transactions begin to use an embedded dfops structure. In the latter model, dfops processing creates a new xfs_defer_ops structure with each transaction and the associated state is migrated across to the new transaction. Fix up xfs_defer_finish() to handle the possibility of the current dfops changing after a transaction roll. Since ->t_dfops is used unconditionally in this path, it is no longer necessary to attach/restore ->t_dfops and pass it explicitly down to xfs_defer_trans_roll(). Update dop in the latter function and the caller to ensure that it always refers to the current dfops structure. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bill O'Donnell <billodo@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-23xfs: return from _defer_finish with a clean transactionDarrick J. Wong
The following assertion was seen on generic/051: XFS: Assertion failed: tp->t_firstblock == NULLFSBLOCK, file: fs/xfs/libxfs5 ------------[ cut here ]------------ kernel BUG at fs/xfs/xfs_message.c:102! invalid opcode: 0000 [#1] SMP PTI CPU: 2 PID: 20757 Comm: fsstress Not tainted 4.18.0-rc4+ #3969 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.1-1 04/01/4 RIP: 0010:assfail+0x23/0x30 Code: c3 66 0f 1f 44 00 00 48 89 f1 41 89 d0 48 c7 c6 88 e0 8c 82 48 89 fa RSP: 0018:ffff88012dc43c08 EFLAGS: 00010202 RAX: 0000000000000000 RBX: ffff88012dc43ca0 RCX: 0000000000000000 RDX: 00000000ffffffc0 RSI: 000000000000000a RDI: ffffffff828480eb RBP: ffff88012aa92758 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: f000000000000000 R12: 0000000000000000 R13: ffff88012dc43d48 R14: ffff88013092e7e8 R15: 0000000000000014 FS: 00007f8d689b8e80(0000) GS:ffff88013fd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8d689c7000 CR3: 000000012ba6a000 CR4: 00000000000006e0 Call Trace: xfs_defer_init+0xff/0x160 xfs_reflink_remap_extent+0x31b/0xa00 xfs_reflink_remap_blocks+0xec/0x4a0 xfs_reflink_remap_range+0x3a1/0x650 xfs_file_dedupe_range+0x39/0x50 vfs_dedupe_file_range+0x218/0x260 do_vfs_ioctl+0x262/0x6a0 ? __se_sys_newfstat+0x3c/0x60 ksys_ioctl+0x35/0x60 __x64_sys_ioctl+0x11/0x20 do_syscall_64+0x4b/0x190 entry_SYSCALL_64_after_hwframe+0x49/0xbe The root cause of the assertion failure is that xfs_defer_finish doesn't roll the transaction after processing all the deferred items. Therefore it returns a dirty transaction to the caller, which leaves the caller at risk of exceeding the transaction reservation if it logs more items. Brian Foster's patchset to move the defer_ops firstblock into the transaction requires t_firstblock == NULLFSBLOCK upon defer_ops initialization, which is how this was noticed at all. Reported-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2018-07-11xfs: remove xfs_defer_init() firstblock paramBrian Foster
All but one caller of xfs_defer_init() passes in the ->t_firstblock of the associated transaction. The one outlier is xlog_recover_process_intents(), which simply passes a dummy value because a valid pointer is required. This firstblock variable can simply be removed. At this point we could remove the xfs_defer_init() firstblock parameter and initialize ->t_firstblock directly. Even that is not necessary, however, because ->t_firstblock is automatically reinitialized in the new transaction on a transaction roll. Since xfs_defer_init() should never occur more than once on a particular transaction (since the corresponding finish will roll it), replace the reinit from xfs_defer_init() with an assert that verifies the transaction has a NULLFSBLOCK firstblock. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-11xfs: refactor dfops init to attach to transactionBrian Foster
Most callers of xfs_defer_init() immediately attach the dfops structure to a transaction. Add a transaction parameter to eliminate much of this boilerplate code. This also helps self-document the fact that many codepaths now expect a dfops pointer implicitly via xfs_trans->t_dfops. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-11xfs: rename xfs_trans ->t_agfl_dfops to ->t_dfopsBrian Foster
The ->t_agfl_dfops field is currently used to defer agfl block frees from associated transaction contexts. While all known problematic contexts have already been updated to use ->t_agfl_dfops, the broader goal is defer agfl frees from all callers that already use a deferred operations structure. Further, the transaction field facilitates a good amount of code clean up where the transaction and dfops have historically been passed down through the stack separately. Rename the field to something more generic to prepare to use it as such throughout XFS. This patch does not change behavior. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-06-06xfs: convert to SPDX license tagsDave Chinner
Remove the verbose license text from XFS files and replace them with SPDX tags. This does not change the license of any of the code, merely refers to the common, up-to-date license files in LICENSES/ This change was mostly scripted. fs/xfs/Makefile and fs/xfs/libxfs/xfs_fs.h were modified by hand, the rest were detected and modified by the following command: for f in `git grep -l "GNU General" fs/xfs/` ; do echo $f cat $f | awk -f hdr.awk > $f.new mv -f $f.new $f done And the hdr.awk script that did the modification (including detecting the difference between GPL-2.0 and GPL-2.0+ licenses) is as follows: $ cat hdr.awk BEGIN { hdr = 1.0 tag = "GPL-2.0" str = "" } /^ \* This program is free software/ { hdr = 2.0; next } /any later version./ { tag = "GPL-2.0+" next } /^ \*\// { if (hdr > 0.0) { print "// SPDX-License-Identifier: " tag print str print $0 str="" hdr = 0.0 next } print $0 next } /^ \* / { if (hdr > 1.0) next if (hdr > 0.0) { if (str != "") str = str "\n" str = str $0 next } print $0 next } /^ \*/ { if (hdr > 0.0) next print $0 next } // { if (hdr > 0.0) { if (str != "") str = str "\n" str = str $0 next } print $0 } END { } $ Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-05-10xfs: adder caller IP to xfs_defer* tracepointsDave Chinner
So it's clear in the trace where they are being called from. Signed-Off-By: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-05-09xfs: defer agfl block frees from deferred ops processing contextBrian Foster
Now that AGFL block frees are deferred when dfops is set in the transaction, start deferring AGFL block frees from contexts that are known to push the limits of existing log reservations. The first such context is deferred operation processing itself. This primarily targets deferred extent frees (such as file extents and inode chunks), but in doing so covers all allocation operations that occur in deferred operation processing context. Update xfs_defer_finish() to set and reset ->t_agfl_dfops across the processing sequence. This means that any AGFL block frees due to allocation events result in the addition of new EFIs to the dfops rather than being processed immediately. xfs_defer_finish() rolls the transaction at least once more to process the frees of the AGFL blocks back to the allocation btrees and returns once the AGFL is rectified. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-12-14xfs: add the ability to join a held buffer to a defer_opsDarrick J. Wong
In certain cases, defer_ops callers will lock a buffer and want to hold the lock across transaction rolls. Similar to ijoined inodes, we want to dirty & join the buffer with each transaction roll in defer_finish so that afterwards the caller still owns the buffer lock and we haven't inadvertently pinned the log. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-09-01xfs: remove the ip argument to xfs_defer_finishChristoph Hellwig
And instead require callers to explicitly join the inode using xfs_defer_ijoin. Also consolidate the defer error handling in a few places using a goto label. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-09-01xfs: rename xfs_defer_join to xfs_defer_ijoinChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-09-01xfs: refactor xfs_trans_rollChristoph Hellwig
Split xfs_trans_roll into a low-level helper that just rolls the actual transaction and a new higher level xfs_trans_roll_inode that takes care of logging and rejoining the inode. This gets rid of the NULL inode case, and allows to simplify the special cases in the deferred operation code. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2016-10-24xfs: defer should abort intent items if the trans roll failsDarrick J. Wong
If the deferred ops transaction roll fails, we need to abort the intent items if we haven't already logged a done item for it, regardless of whether or not the deferred ops has had a transaction committed. Dave found this while running generic/388. Move the tracepoint to make it easier to track object lifetimes. Reported-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-19xfs: defer should allow ->finish_item to request a new transactionDarrick J. Wong
When xfs_defer_finish calls ->finish_item, it's possible that (refcount) won't be able to finish all the work in a single transaction. When this happens, the ->finish_item handler should shorten the log done item's list count, update the work item to reflect where work should continue, and return -EAGAIN so that defer_finish knows to retain the pending item on the pending list, roll the transaction, and restart processing where we left off. Plumb in the code and document how this mechanism is supposed to work. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2016-08-30xfs: track log done items directly in the deferred pending work itemDarrick J. Wong
Christoph reports slab corruption when a deferred refcount update aborts during _defer_finish(). The cause of this was broken log item state tracking in xfs_defer_pending -- upon an abort, _defer_trans_abort() will call abort_intent on all intent items, including the ones that have already had a done item attached. This is incorrect because each intent item has 2 refcount: the first is released when the intent item is committed to the log; and the second is released when the _done_ item is committed to the log, or by the intent creator if there is no done item. In other words, once we log the done item, responsibility for releasing the intent item's second refcount is transferred to the done item and /must not/ be performed by anything else. The dfp_committed flag should have been tracking whether or not we had a done item so that _defer_trans_abort could decide if it needs to abort the intent item, but due to a thinko this was not the case. Rip it out and track the done item directly so that we do the right thing w.r.t. intent item freeing. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reported-by: Christoph Hellwig <hch@infradead.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-03xfs: add tracepoints for the deferred ops mechanismDarrick J. Wong
Add tracepoints for the internals of the deferred ops mechanism and tracepoint classes for clients of the dops, to make debugging easier. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-03xfs: move deferred operations into a separate fileDarrick J. Wong
All the code around struct xfs_bmap_free basically implements a deferred operation framework through which we can roll transactions (to unlock buffers and avoid violating lock order rules) while managing all the necessary log redo items. Previously we only used this code to free extents after some sort of mapping operation, but with the advent of rmap and reflink, we suddenly need to do more than that. With that in mind, xfs_bmap_free really becomes a deferred ops control structure. Rename the structure and move the deferred ops into their own file to avoid further bloating of the bmap code. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>